1. Field of the Invention
The present invention generally relates to a motion editing system and method and a computer program, destined from supporting the motion creation and edition to describe a predetermined motion pattern of a robot, and more particularly to a motion editing system and method and a computer program, for a legged locomotion robot device which conducts various kinds of work.
2. Description of the Related Art
A mechanical apparatus designed based on the electrical and magnetic engineering to mimic human motions is called “robot”. The term “robot” is said to have been derived from a Slavic word “ROBOTA (slave machine)”. In Japan, the robots have become more widely prevalent at the end of 1960s. Many of such robots were industrial ones such as the manipulators and conveyance robots destined for automation and unmanning of the production operations in factories.
The recent researches and developments of the legged locomotive robots designed to have the physical mechanism and motions of bipedal upright-walking animals such as human beings, monkeys, etc., and it is more and more expected that such legged locomotive robots can be used in the practical applications. The bipedal motion in an upright posture is more unstable and difficult to control in posture and walking than the motions on crawlers, four or six feet. However, the bipedal upright motion is more advantageous in the flexible motion over irregular ground surfaces, irregular access routes on which there exist obstacles, and stepped surfaces such as a stepway or ladder.
Also, the legged locomotive robots designed to implement the biological mechanism and motions of the human being is generally called “humanoid robot”. The humanoid robot can support the human activity in the residential environment and other daily life, for example.
Almost all the human working spaces and dwelling spaces are defined for compliance with the body mechanism and behavior of the human being making bipedal upright-walking, and thus have many barriers against the current mechanical systems using wheels or any other driving devices as the moving means. Therefore, to work for the human beings and also for a further acceptability in the human dwelling spaces, the mechanical systems or robots should desirably be able to move in nearly the same range as the human moving range. It is considerably expected just in this respect that the practical applicability of the robots can be attained.
The recent legged locomotion robots have a high capability of information processing. Hence, such a robot itself may be considered as a computer system. In other words, a series of complicated moving sequences comprised of motion patterns performed by a robot or a plurality of fundamental motion patterns in combination, that is, a motion, is formulated for the robot by making similar work to the computer programming.
Therefore, for further prevalence of robots, it is essential to popularize many motion data for operation of the robots. Accordingly it is demanded to build a development environment for edition of robot motions.
Robots will no doubt be used more widely in the industrial field as well as in the general households and daily life. As regards the entertainment robot products among others, choreographers and designers should desirably be able to create motion contents even with no great knowledge of the computer, computer programming and motion control, and common consumers will buy such robots for their amusement. For such common users, there should desirably be provided a supporting tool for creating and editing a sequence of operations for a robot relatively easily and efficiently by an interactive procedure, that is, a motion editing system.
A robot includes a plurality of control points such as joints. Therefore, by making input of a position and speed (joint angle and angular speed) of each of the control points, it is possible to edit a robot motion. In this respect, the edition of robot motions is similar to the creation of an animation of a character in a computer graphic. Naturally, however, an motion in a virtual space is different from a real motion. With only the articulation being changed, the legged locomotion robot cannot be made to perform any user-desired motion. The robot should be able to support itself stably on the feet in making a motion without falling down. In other words, the robot-motion edition should be able to have the robot keep a stable posture in making a motion while making sure that the motion is being positively performed by the robot itself.
Many legged locomotion robots have applied therein ZMP (zero moment point) as a stability criterion. With this technology, a point where the moment is zero is detected inside a support polygon formed between a sole touchdown point and floor or ground surface (cf. “LEGGED LOCOMOTION ROBOTS” by Miomir Vukobratovic). In the case of bipedal legged locomotion robots, since the support polygon is extremely small, it is very difficult to stabilize the posture of the robots.
There is already proposed a motion editing system to edit a robot motion by entering values for the control points of the robot from a monitor screen. However, there is not yet available any robot-motion editing system intended for use to have an actual robot perform an edited motion and which is also capable of checking the posture of the actual robot and correcting the actual-robot motion to stabilize the posture. If the robot cannot keep any stable posture with the edited motion and it cannot perform the edited motion itself, the motion edition is substantially useless.